Field of the Invention
Embodiments of the present invention relate to a method of delivering, by a media server, suitable media or transforming the format of media and delivering the transformed media based on reception status information received from a client when the media server includes one or more media having different transport characteristics or sends media on which the format of content can be variably transformed in accordance with a service form to the client.
Discussion of the Related Art
Media may have various forms and have different characteristics when the media are transmitted. For example, high-picture quality media require a high transfer rate. In such high-picture quality media, a client needs to be able to be connected to a network over which media can be received at a high transfer rate. Furthermore, the client needs to be equipped with a capability capable of processing the high-picture quality media. Accordingly, the same content requires a different transfer rate and processing capability depending on picture quality.
If a client is a terminal having mobility, the terminal may have a different reception capability depending on an accessed network. Furthermore, if a network to which a terminal is connected is a low-speed network, such as a mobile communication network, the terminal can receive only low-quality media. If a network to which a terminal is connected is a high-speed network, such as 802.11n, the terminal can also receive high-quality media. Furthermore, the speed of a network itself may be problematic, but the Internet may have a different network transfer rate depending on a network traffic situation. Accordingly, in MPEG, Dynamic Adaptive Streaming over HTTP (hereinafter referred to as MPEG-DASH) technology has been standardized.
MPEG-DASH is technology in which media to be adaptively received by a terminal are selected and controlled. Only high-picture quality media may not be always received because low-picture quality media in addition to high-picture quality media can be received depending on a network environment. As one of methods for solving such a problem, Korean Patent Laid-Open Publication No. 10-2013-0127211 (Nov. 22, 2013) entitled “Adaptive Media Streaming Transmission Method and Apparatus for Multi network Environment” discloses that media data is generated by encoding specific content in a plurality of layers, the generated media data is separated into the layers, and the media data separated into the layers is streamed and transmitted to a media reception apparatus over a plurality of networks.
However, a media server needs to be able to dynamically send media having different transport characteristics depending on a terminal's reception capability. Accordingly, there is a need for a method of recognizing, by the media server, the status of the terminal and directly controlling media streaming.